TESAIoT PSE84 Programmer v0.2.9

Picks the correct BSP / flash-loader file from kit_name (via fw-loader --info) instead of guessing from the chip's security_class. The previous mapping assumed S2 ⇒ AI Kit and S4 ⇒ EVAL EPC2, but an EVAL EPC2 board reports PSE846GPS2DBZC4A · S2 and was being flashed with the AI Kit's FLM. The two FLMs only differ in 32 bytes of FlashDevice config so it worked by luck, but v0.2.9 now uses the right file for each kit. Also removes the v0.2.7 partial-update warning, which was misdiagnosis (every working PSE84 hex omits RRAM extended_boot because it is factory-provisioned, not in user hex files). Local Flash now treats hex files cleanly and the boot question is left to the firmware. Same install rules as prior releases (macOS first launch: right-click → Open; Windows SmartScreen: 'More info' → 'Run anyway').